FAQs

How can you clean a photomask?

If the masks are not too heavily contaminated, acceptable results can be achieved with the following technique:

First soak the mask in a solution of Decon 90 for approximately 10-15 minutes

Wipe carefully with a clean, pre-wetted, PVA sponge

Rinse the mask in running filtered D.I. water (starting by continuing the wiping process under running D.I. water if possible)

Leave to dry in a clean air environment

You can also use our photomask cleaning service, particularly recommended for heavily contaminated masks

Our cleaning processes are based on the use of a sulphuric acid / hydrogen peroxide mix

Our UK and Fremont facilities use purpose designed automatic single substrate mask cleaning tools such as the HMR900 system, manufactured by HamaTech, now part of SUSS MicroTec

HMR900 tools clean the mask by dispensing a small quantity of sulphuric acid and hydrogen peroxide onto one surface (facing upward) while it is slowly rotated in the process chamber. The mask is then rinsed free of chemicals, sprayed with a high pressure ionised (with ammonia) water spray, brushed with a rotating PVA sponge brush, rinsed again and finally spun dry.